A number of agents are known to be useful in promoting growth and weight gain in domestic animals. Certain agents, for example, compositions containing .alpha.-hydroxy-.gamma.-methylmercaptobutyric acid described in U.S. Pat. No. 2,745,745 issued May 15, 1956, are known to promote growth by improving feed efficiency. Other agents such as, for example, anti-bacterial agents are said to be useful in promoting growth of animals which may be the result of removing a restriction on normal growth. Estrogens, or estrogenic substances, progestogens and androgens, particularly testosterone propionate are also known to be useful in promoting growth in animals. It is reported that the weight gain in steroid fed, for example, estrogen fed poultry is likely the result of increased fat depositions. In ruminants it is reported that increased weight gains resulting from the administration of steroids is likely due to the anabolic effect of the steroids since there is an increase in muscle tissue and bone in such animals with less fat in the carcasses. Although testosterone propionate is known to be effective in promoting growth in animals the use of said compound results in masculinization of the muscle fiber due to the androgenicity of the compound. The compounds employed in the present invention provide a method of promoting the growth of poultry and ruminants without any masculinizing effect on the muscle fiber.
Some of the compounds employed in the present invention, for example, 19-hydroxyandrost-4-ene-3,17-dione and the 19-oxo derivative thereof have been involved in numerous in vitro studies wherein their role in the metabolism of androgen has been investigated. Additionally, 19-hydroxyandrost-4-ene-3,17-dione is reported to have been administered to two healthy male subjects each twenty-one years of age (J. Clin. Endocrinol. Metab. 28, 1401 (1968)). In U.S. Pat. No. 3,235,573, issued Feb. 15, 1966, and U.S. Pat. No. 3,449,381, issued June 10, 1969, is reported 3-oxo-17.beta.-hydroxyandrost-4-en-19-al wherein the utilities disclosed are anabolic-androgenic activity, inhibition of pituitary gonadotrophins and adrenocorticotrophin, antiestrogenic, blood, liver and adrenal cholesterol lowering properties, control of fertility and psychotic conditions, and appetite stimulants. Although 3-oxo-17.beta.-hydroxyandrost-4-en-19-al has been reported to have anabolic-androgenic activity the present invention would not be suggested thereby in view of our findings that said compound is effective in growth promotion in animals without any masculinizing effect on the muscle fiber which would be an indication of a lack of or only limited androgenic effects.